Kate Middleton visited Bletchley Park on Tuesday afternoon to view its new D-Day: Interception, Intelligence, Invasion exhibition, which marks the 75th anniversary of the historic landings.
With blue skies over London, the mum-of-three donned a perfect spring look, recycling her vintage-inspired blue shirt dress which featured white polka dots and matching white collar.
The 37-year-old first debuted the midi dress by London-based Alessandra Rich last year, when she wore it for a series of family portraits to commemorate Prince Charles' birthday.
However, Tuesday was the outfit's first official outing and Kate paired the statement number with blue Emmy London shoes, a matching clutch bag and trendy Annoushka pearl earrings.
The Duchess of Cambridge is not the only celebrity fan of the dress. In fact, it became quite the cult item in 2018, seen on Meghan Markle's Suits co-star Abigail Spencer at the royal wedding, Ivanka Trump during a trip to Illinois and Sarah Jessica Parker out and about in New York.
Unsurprisingly, the dress has sold out, but the designer has bought out a new, extremely similar, design.
The latest creation, featuring embellished buttons and a black collar, is available for £1,771.